JPH067007B2 - Waste melting furnace slag facility - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric resistance melting furnace for melting and treating municipal waste, and more particularly to a slag facility of the melting furnace.

[Conventional technology]

The mainstream of waste such as municipal waste is the method of landfilling after incineration. However, since it is difficult to secure landfill sites in recent years, a melting treatment method for reducing the volume of waste has been drawing attention.

There are two methods of melting treatment of these wastes, an arc furnace method and a resistance furnace method, but the former method has the following problems. That is, 1) Voltage and current are unstable due to arc discharge.

2) The electrode is moved up and down frequently to maintain arc discharge, and it is difficult to follow it.

On the other hand, the latter method has been conventionally used for manufacturing iron alloys and the like, and its heating method is an electric melting furnace for obtaining Joule heat by embedding an electrode in a material to be melted and energizing it. There are no problems with the above arc furnace.

The molten metal slagging method in this electric resistance type melting furnace is
There are two types: intermittent type and continuous type.The former intermittent type is a technology that has already been completed in the production facility for ferro-alloys, etc. There is. However, regarding the continuous slag method, although there are actual examples for simple substances, there are no examples containing substances with completely different properties such as metal and slag such as incinerated ash, and the following difficulties is there.

1) The slag erosion prevention measures differ depending on the physical properties of the metal and the slag mainly composed of SiO ₂ , A ₂ O ₃ , CaO, etc.

2) It is difficult to keep up with the amount of slag that has been incinerated.

3) Repair time is required.

4) In case of intermittent slag, tapping and closing work are frequent.

On the other hand, the melting treatment method has a high temperature of 500 to 700 ° C. as compared with the incineration treatment method, which increases the risk,
Skill level is also required. Therefore, there is an increasing need for a continuous slag system that can reduce the work load as much as possible.

Japanese Patent Application Laid-Open No. 56-77 discloses a closed arc furnace in which slag is continuously discharged without tapping.
No. 611 has a slag opening in the center of the hearth of the furnace shell, the upper end of this slag opening is surrounded by a dam-like dam, and an airtight device is attached to the slag opening. An arc furnace for waste treatment is disclosed in which a shell or a furnace lid is provided with a gas outlet and a waste inlet.

The above arc furnace is made in view of the above problems,
Since the outlet is located at the bottom of the furnace, the arc furnace must be installed at a high place, and the mechanism such as sealing is complicated.

Therefore, when incinerating municipal waste and melting the incinerated ash in a melting furnace to reduce the volume, there has been a demand for the development of a facility for continuously discharging the ash with a simpler mechanism.

[Problems to be solved by the invention]

The present invention has been made in view of the above-mentioned problems of the conventional techniques, and when treating wastes containing components such as metal and slag, like incineration ash, in an electric resistance type melting furnace, the slag It is to provide the equipment which makes the work continuous and rationalizes the work.

[Means for solving problems]

The present invention relates to an electric resistance type melting furnace that melts waste incineration ash, forms a slag layer and a metal layer, and slags the molten slag, in a furnace wall portion of the melting furnace, a metal slag discharge port and the discharge port. A slag discharge facility in the waste melting furnace, characterized in that a slag discharge port is provided in the upper part, and a metal / slag overflow tank and a slag overflow tank that communicate with each discharge port and adjust the discharge amount are provided. Is.

[Action]

Since the slag spout in the conventional electric resistance type heating and melting furnace is provided in one position in the horizontal direction, continuous slag has the following drawbacks.

1) If the slag diameter is large relative to the melting rate, the slag will slag quickly and a layer will not be formed. Further, even unmelted material is discharged at the same time.

2) Since the diameter of the slag is adjusted to the melting amount, the diameter becomes small and it is easy to clog.

3) It is necessary to intermittently extract metal from another outlet.

The present invention solves the above-mentioned drawbacks by adopting the above configuration.

A slag layer can be formed by providing metal slag and slag outlets on the top and bottom, and the slag that overflows from the upper part flows into the lower metal slag overflow tank, melting the melted material with a low metal content. Even when the metal layer does not drop in temperature, it can be slagged. In addition, even if the amount of processing is small, the size of the outlet for the mud gun is set,
Intermittent slag is also possible, and by providing a plurality of similar slag ports, it is a slag facility for a waste melting furnace that enables continuous operation without stopping the furnace.

The present invention will be described below with reference to the drawings which are examples of embodiments.

〔Example〕

 FIG. 1 is an explanatory diagram of an apparatus according to an embodiment of the present invention.

In the figure, reference numeral 1 is an electric resistance heating type electric furnace, which is insulated from the outside air by a furnace lid 2 provided on the upper part of the furnace. Three
Is a metal layer and 4 is a slag layer. Incinerated ash of melted material 5
Are charged so that they can be evenly distributed in the furnace from a plurality of charging ash shouts 7 provided in the upper part. Reference numeral 6 denotes a heating electrode, which is embedded in the melted object 5 so that it can be heated and melted by Joule heat. 8 is an exhaust gas duct, 9 is a metal slag overflow tank, 10 is a slag overflow tank, 11 and 12 are slag outlets for metal slag and slag, 13 is a metal outlet, and 14 is a repair opening, which is always open. Is to be closed and opened if necessary. Reference numeral 15 is a rising weir used at the start of melting.
6 and 17 are a mud gun for opening and an opener, respectively.

In the figure, Ha is the charging thickness of the melted material, Hs is the slag layer thickness,
Hm is the metal layer thickness from the bottom of the slag / metal overflow tank to the bottom of the slag layer, and Hsm is the height of the metal / slag layer in the metal / slag overflow tank.

Next, the operation of the melting furnace of the present invention will be described. When the waste incineration ash is charged and the electrodes 6 are energized to start melting, the metal slag starts to accumulate in the bottom of the melting furnace 1. In this case, the rising weir 15 is provided until the metal reaches the overflow level of the metal slag overflow tank 9 as shown by the two-dot broken line, and then removed.

As shown in the figure, a metal layer 3 and a slag layer 4 are formed, and when reaching each level, metal overflows from the metal / slag overflow tank 9 and slag overflows from the slag overflow tank 10.

The overflowed slag falls into the metal slag overflow tank 10 filled with metal protruding downward as shown by the arrow, and is discharged out of the furnace while entraining the metal. Therefore, the slag and the metal are always mixed in the metal / slag overflow tank.
Even if the amount of metal is very small, the slag is mixed and the temperature drop can be avoided.

Here, the height relationship of each layer can be expressed by the following equation.

Hsm x ρ _sm <Ha x ρ _ash + Hs x ρ _s + Hm ρ _F ρ _sm : Specific gravity in a state where metal and slag are mixed ρ _ash : Specific gravity of melted material ρ _s : Specific gravity of slag ρ _F : Specific gravity of metal The slag layer thickness is 100-300 mm, preferably 200-300 mm, because the melting furnace is heated by Joule.
It is necessary to always hold mm so as to contribute to energization of the electrode 6 and stabilization of voltage and current.

According to the slag facility of the present invention, when the amount of slag increases, the slag overflows from the slag overflow tank 10, and when the amount of metal increases, the metal slag overflows from the metal / slag overflow tank 9, and the slag overflows depending on the melting amount. Since the slag layer is discharged from the overflow tank, it is possible to form the slag layer with the above-mentioned constant thickness, the frequency of ascending and descending the electrode 6 is reduced, and the electric power used is stabilized to enable continuous operation.

In addition, each outlet has a diameter that can be sufficiently discharged even at the time of maximum treatment, and can also be adjusted to a diameter that is not affected by adhesion of slag or the like.

Since each overflow portion comes into contact with the outside air, it may be kept warm. In addition, purging may be performed so as not to contact the outside air.

Further, by preparing a plurality of similar outlets and alternately using them in preparation for repairing the outlets, the furnace can be continuously operated without stopping for a long period of time.

〔The invention's effect〕

The waste smelting facility of the waste melting furnace of the present invention enables a large volume reduction of waste incineration ash such as municipal waste, and can stably form the slag layer of the electric resistance type melting furnace. The frequency of lifting and lowering of the electrodes is reduced, and the operating power can be stabilized, enabling continuous operation. Further, the present invention is a useful facility that can be applied not only to melting waste but also to industrial electric furnaces and the like aiming at continuous slag.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a slag facility of the waste melting furnace of the present invention. 1: Electric resistance type melting furnace, 3: Metal layer, 4: Slag layer,
5: melted material, 6: electrode, 9: metal slag overflow tank, 10: slag overflow tank, 11: metal slag outlet, 12: slag slag outlet, 15: rising weir,
17: Mad gun, Ha: Charged thickness of molten material, Hs: Slag layer thickness, Hm: Metal layer thickness from bottom of slag / metal overflow tank to bottom of slag layer, Hsm: Metal in metal / slag overflow tank -The height of the slag layer.

Front page continuation (72) Inventor Katsuo Kawabuchi 1988-72 Kitahasakucho, Midori-ku, Yokohama-shi, Kanagawa 1988-72 (72) Inventor Hirotsugu Kubo Tokiwadai, Hodogaya-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Akio Nakamoto Yokohama, Kanagawa Prefecture 677-5, Fukaya-cho, Totsuka-ku, Japan (72) Inventor Toshio Shiina 6-15-50, Kawabe-cho, Ome-shi, Tokyo (72) Inventor Hachiro Fujishiro 532 Oshimizu, Tateyama-machi, Nakashinkawa-gun, Toyama Prefecture (72) Inventor, Ando People 1-7-12 Kyogamine, Itoigawa City, Niigata Prefecture (72) Inventor Yoichi Hosaka 13-2 Takai, Aomi-cho, Nishikubiki-gun, Niigata Prefecture (2) Inventor Ryoichi Ueno 1137, Shin-cho, Nishikubiki-gun, Niigata Prefecture

Claims (1)

[Claims] 1. An electric resistance melting furnace in which waste incineration ash is melted to form a slag layer and a metal layer, and molten slag is discharged. In a furnace wall portion of the melting furnace, a metal slag discharge port and a metal slag discharge port are provided. A slag discharge port is provided above the discharge port, and a metal / slag overflow tank and a slag overflow tank that communicate with each of the discharge ports and adjust the discharge amount are provided. Slag equipment.